After a NYTimes trend piece anecdotally discussed the disparity in January, citing Wikipedia’s male-heavy geek culture roots as the source, this intrepid bunch decided to actually do the numbers, pulling the data on editors’ gender from their profile information. And indeed, of the editors who joined in 2009 and disclosed gender, only about 16% were female, and they made only 9% of the cohort’s edits. Looking at signups over time, the researchers also saw that Wikipedia’s gender gap isn’t closing, in contrast to many social media sites, where women are now more likely to participate than men. This may be because Wikipedia looks like a slightly chilly place for new female users: self-identified women were more likely to get their early edits reverted than men were.

It’s neat that we now have real numbers in the discussion of Wikipedia’s gender politics. But there are few problems with a study voluntarily disclosed information: if you’re a woman, and you’ve already begun to suspect that Wikipedia is primarily a man’s operation, why would you state your gender at all? The vast majority of editors don’t volunteer that, preferring perhaps to have their work judged by the community without having gender on the table, and one has to wonder if those who declared might not be the sort who spent a lot of time on Wikipedia in the first place.

Compare the Wikipedia entry for Teenage Mutant Ninja Turtles with the entry for friendship bracelets, and you’ll find a disparity: the sword-swinging reptiles have garnered far more words than the school-days token of friendship. The Wikimedia Foundation, which runs Wikipedia, sees disparities like these as the outcome of a much more serious one: only about 13 percent of Wikipedia’s hundreds of thousands of contributors are women.

This gender gap was discovered in a recent study of Wikipedia entries (pdf). The average contributor, it turns out, is a mid-twenty-something-year-old male. To begin to close the gender gap, Wikimedia Foundation Executive Director Sue Gardner has set a goal for the company: to increase the number of female writers to 25 percent in the next four years.

Her effort is not diversity for diversity’s sake, she says. “This is about wanting to ensure that the encyclopedia is as good as it could be,” Ms. Gardner said in an interview on Thursday. “The difference between Wikipedia and other editorially created products is that Wikipedians are not professionals, they are only asked to bring what they know…. Everyone brings their crumb of information to the table,” she said. “If they are not at the table, we don’t benefit from their crumb.”

Are you a professional hoping to alienate others in your field? Perhaps you could try the technique used by a Canadian doctor who posted all 10 inkblots used in Rorschach tests to Wikipedia, along with complete descriptions of the most common responses to the images.

Although some psychologists debate the usefulness of the test, which was invented in 1921, it remains the second most-used psychological test today. Many in the field worry that patients who come into the Rorschach test with preconceptions could “game” the test, resulting in a skewed diagnosis.

For [psychologists], the Wikipedia page is the equivalent of posting an answer sheet to next year’s SAT. They are pitted against the overwhelming majority of Wikipedia’s users, who share the site’s “free culture” ethos, which opposes the suppression of information that it is legal to publish…

What had been a simmering dispute over the reproduction of a single plate reached new heights in June when [ER doctor] James Heilman…posted images of all 10 plates to the bottom of the article about the test, along with what research had found to be the most popular responses for each.

We’re not quite sure how posting the inkblots online would benefit anyone. But then, we can’t know what was going on in the doctor’s head…maybe we should recruit a couple of psychologists to figure it out.